Anon Sirisaengtaksin, PTTGC chief executive officer, said the yellow substances were immediately taken from the beaches to the company’s lab which confirmed that they were not oil residues.
A recent oil spill from a PTTGC offshore pipeline damaged the environment in the area and at nearby Samet Island.
Mr Anon said the company has also collected black solid materials from the beaches in Ban Kaen Samet and Suan Son to check if they were residues from the oil slick. Results of lab tests are not yet known.
He said PTTGC was determined to sustainably restore the environment and ecological systems after they were affected by the slick.
Rayong governor Vichit Chartpaisit said researchers from the Fisheries Department and the Marine and Coastal Resources Department have surveyed Ban Kaen Samet and Suan Son beaches, and asserted there were no oil residues in the areas.
However, researchers will conduct thorough tests of the residues in a lab to ensure that they are not dangerous to the environment, he said.